The desert sky was an odd brooding gray as we pulled into McDonald’s, the arches looming bright and preternaturally yellow out of the dusty landscape. By the time we’d finished our McKebab sandwiches — much better than you might expect — it was raining: a steady, drumming, respectable rain.

It almost never rains in Israel’s Arava Valley, the driest, hottest and southernmost part of Israel. I was about to meet a desert botanist, Elaine Solowey, so I was anxious to hear what she’d say. I assumed she’d be excited about the rain and wax rhapsodic about making the desert bloom and all that.

But no, she seemed annoyed. She pointed out that a light rain just moves the surface salts down to the plant roots and that you then have to use more water to get rid of it. “What I wish is for rain in the north where it can do some good.”

I spent the afternoon with Solowey at Kibbutz Ketura, where she’s lived since its founding in the early 1970s. Ketura is also now home to the Arava Institute for Environmental Studies, where Solowey runs the Center for Sustainable Agriculture.

Solowey, who was raised in California’s Central Valley — another hot locale but one with considerably more water sources and more fertile — has a no-nonsense manner that can come off as brusque. Fair enough: When you’ve spent your career working some of the world’s least forgiving soil, you’re unlikely to suffer fools — gladly or otherwise.

Solowey made news in 2005 when she accomplished what was thought to be botanically impossible: germinating a 2,000-year-old date seed that had been found during an excavation at Masada. She showed me earlier this year the spot where Methuselah, as the sapling is known, was to be planted in the ground — noting that it will be on a security system.

Solowey is a champion of improbable plants. Her “experimental orchard,” a nursery for mostly forgotten and endangered desert species, includes 1,000 varieties of trees, cacti and grains. The orchard is a small Eden in the wilderness, lush with exotic fruit species — sapodilla, yellow pitaya, Yemenite pomegranate — and other productive plants that thrive in arid, saline soil.

Nearby, next to the rows of date palms that represent one of the kibbutz’s sources of income, is the broad acacia tree that started it all. The tree was about to be taken down to make room for the dates, but Solowey protested — she saw that this was not just a tree but an entire ecosystem. Birds nested there, jackals slept in its branches, grasses flourished under its canopy.

Such observations launched her quest to understand desert plants and explore their ecological and economic potential — a potential she believes remains largely untapped.

“More than 15,000 edible, medicinal or useful products come from perennial plants that have not been domesticated,” she wrote in her 2003 book, Small Steps Towards Abundance: Crops for a More Sustainable Agriculture. Her research focuses on identifying and nurturing trees and other perennials that yield food for people and livestock, as well as serve other functions like building soil and stopping erosion. A particular interest is cultivating medicinal plants; she works closely with the Natural Medicine Research Unit at Hadassah Hospital in Jerusalem on domesticating wild medicinal plants and preserving endangered species with medicinal properties. She pointed out a row of neem trees, members of the mahogany family, which, she said, have so many medical uses in India they’re called the “pharmacy of the village.”

“They also act as a windbreak for the arganias,” she said. “We have 300 of them, and I’m glad.”

Many orchard specimens have been forgotten to the point of extinction. “There are plants here in the south that are going extinct, and no one is noticing,” she said. “As for most of those, we don’t know the duties they perform, the animals that live in them. Why in the world should we let them die when with so little effort we can keep them alive?”

She has a grove of 150 marula trees from Africa, a prolific producer whose fruit is useful for liqueurs and animal fodder. Another current favorite is the Argania spinosa, from Morocco, known for nuts that make high-quality oil — and which, significantly, survives on very little water.

“We’re hoping to find people new crops to make a living on,” she said. “Until we get a handle on these trees, get a sense of the life cycle, we can’t do it.”

She says she’s always on the lookout for plants that are “salt tolerant, heat tolerant, dry tolerant and pretty tough. Changing the desert for our plants is expensive and not sustainable. We should only be growing things here that are biologically appropriate.” This includes domesticating plants with high-value crops, like dates: “Dates need seven months of no rain. If you’ve got lemons, make lemonade. What we have is 350 days of full sunlight.”

Her efforts span borders. For example, in a joint program with the Jordan University of Science and Technology, her program exchanges seeds of now-rare native plants for research and looks for salt-tolerant, water-saving plants that might do well in the region. One of her projects involving medicinal species involves Tibetan plants, and as a result she gave the Dalai Lama a tour of her orchard.

Given the range of benefits from trees, and, compared to annual crops, how much less energy, water and labor they require, Solowey believes people should devote more effort to long-lived plants, and especially in a place like Israel. This she learned after years on the kibbutz. “Because of the Mediterranean climate, it’s easier to grow fruits than vegetables here,” she said. “Two-thirds of Israel is desert or semi-desert. Very few vegetables like that climate.”

Because, in its early years, the kibbutz banked on crops like lettuce, cucumbers and tomatoes that take lots of work in that environment, everyone had to pitch in, she recalled. “We had to do vegetable work after we came home from our other jobs. And what did we get? One-shekel-20 a kilo.”

She’s since decided annual crops were a mistake. “Ecologically, the more fragile the ecosystem, the more easy it is to mess it up. The soil dries, blows away more easily, gets compacted by tractors, and the minerals get washed away. If you abuse it, it turns into a parking lot.”

One inspiration of hers is the work of J. Russell Smith, an American geographer and economist who observed how conventional agriculture ravaged the landscape around the world, leaving gullies and hills of sand where there had been plants. In his classic 1929 book Tree Crops, he portrayed trees as the answer.

“When you replant [with trees], you slow or stop the wind, you stop the loss of topsoil and erosion from rain,” says Solowey. “The only way you can stop desertification is with plants, rows of trees. In 10 years, the neem tree makes you several inches of topsoil, and it forms a microclimate that holds moisture. Acacias are nitrogen-fixing trees, and can be used for land restoration. It drops its leaves before the rainy season [which turns into] litter so rich other plants grow around it. A wonderful thing, an acacia tree.”